Delete Documents - CRUD Operations

In MongoDB, deleting documents is part of the CRUD (Create, Read, Update, Delete) operations. In this page, we will discuss how to delete documents from a MongoDB database.

Syntax

The basic syntax for deleting a document in MongoDB is as follows:

db.collection.deleteOne(
   <filter>,
   <options>
)

The deleteOne() method deletes a single document that matches the specified filter. You can use deleteMany() method to delete multiple documents with a single operation.

Example

Consider the following inventory collection with sample data:

{ "_id" : 1, "item" : "apple", "qty" : 5 }
{ "_id" : 2, "item" : "banana", "qty" : 10 }
{ "_id" : 3, "item" : "orange", "qty" : 2 }
{ "_id" : 4, "item" : "peach", "qty" : 8 }

To delete a single document that matches a specified filter, you can use the deleteOne() method as shown below:

db.inventory.deleteOne(
   { "item": "banana" }
)

This will delete the document with "item" value of "banana" and return a DeleteResult object.

Output

The DeleteResult object contains information about the delete operation, including the number of documents deleted, and the acknowledged status of the operation.

Explanation

Deleting a document from a MongoDB collection removes the document from the collection and the database. MongoDB provides various methods to delete documents from a collection, including deleteOne() and deleteMany() methods. You can use these methods to delete one or more documents that match a specified filter.

Use

Deleting documents in MongoDB can be useful for removing outdated or irrelevant data that is no longer needed by your application. This can help to free up disk space and improve overall performance.

Important Points

• You can use deleteOne() method to delete a single document that matches a specified filter.
• The deleteMany() method can be used to delete multiple documents with a single operation.
• Deleting documents deletes the document from the collection and the database.

Summary

In this page, we discussed how to delete documents from a MongoDB database using the deleteOne() method. We covered the syntax, example, output, explanation, use, important points, and summary of the delete operation. By removing unnecessary data, you can improve the performance and efficiency of your application.